Refrigerator appliance with pull-out trolley

ABSTRACT

A refrigerator appliance includes: a refrigerated chamber, a trolley that is slidingly mounted in the refrigerated chamber in such a way that the appliance can be in a closed position, wherein the lid of the trolley covers an upper opening of the refrigerated chamber, and in an open position, wherein the tray of the trolley is basically disposed at the same level as the upper opening of the refrigerated chamber in order to collect objects from the tray, a lifting system connected to the trolley, and a refrigeration system. The trolley has sliding means slidingly mounted in slides that extend vertically in lateral walls of the refrigeration chamber in order to permit the guided sliding of the trolley. The lifting system includes an electric motor, a worm screw and a female screw.

The present invention relates to a refrigerator appliance with pull-out trolley used to refrigerate various types of products, namely bottles.

Refrigerators are known on the market, which are used to contain food products and beverage bottles at a controlled temperature. This type of appliances generally comprises a door that is opened by the user in order to collect the products contained in the refrigerated compartment. This operation is not comfortable because the user does not have a place where to position the collected objects; moreover, the opening of the door changes the climatic conditions of the refrigerated compartment.

These drawbacks are at least partially solved by refrigerators provided with a pull-out trolley where the refrigerated objects are disposed. An actuation system that is controlled by the user pulls out the trolley in such a way that the user can collect the objects from the trolley.

The patent documents U.S. Pat. No. 2,895,311, WO2007/054131 and WO2009048437 disclose refrigerators with a pull-out trolley, wherein the trolley is lifted by an elevator system that is actuated by an electric motor. The movement of the trolley is exclusively guided by linear actuators, is imprecise and subject to jamming, especially if only one linear actuator in central position is used, because the trolley projects from the linear actuator.

Moreover, the refrigeration system of these refrigerators is similar to the one of a domestic refrigerator appliance, and consists in a plate evaporator that is integral with the body of the refrigerated chamber. Such a traditional refrigeration system is not efficient in combination with a pull-out trolley because it does not distribute cold uniformly. In fact, if the evaporator is integral with the bottom wall of the refrigerated chamber, the lower portion of the refrigerated chamber is colder than the upper wall. In such a traditional refrigeration system, the temperature increases rapidly when the trolley is actuated, and is restored slowly when the trolley is lowered, causing the formation of frost.

U.S. Pat. No. 4,848,091 discloses a refrigerated table-bar comprising a body with an upper refrigerated chamber and a lower technical compartment. The refrigerated table-bar comprises a refrigerating unit to refrigerate the upper chamber. A partition is mounted in the refrigerated chamber with possibility of sliding vertically. The partition comprises an upper tray and a lower tray in order to support objects to be refrigerated. A table top is integral with the partition in such a way that the refrigerated table-bar can be in a closed position, wherein the table top closes the body on top, and in an open position, wherein the lower tray is basically at the same level as an upper opening of the upper chamber in order for the user to collect objects from the trays. The refrigerated table-bar comprises a vertical lifting system comprising a gas spring disposed inside an external tube disposed centrally in the upper chamber and connected to the partition. The external central tube is moved by an electromagnetic actuator of solenoid type in order to raise and lower the partition. U.S. Pat. No. 4,848,091 is impaired by a drawback, which consists in the fact that the lifting system of the partition is exclusively actuated by the gas spring disposed in the external central tube that is moved by the solenoid actuator. Such a movement is imprecise and subject to jamming because the trays of the partition protrude from the external central tube and the peripheral part of the trays tends to bend.

U.S. Pat. No. 2,200,502 discloses a refrigerator comprising a basket that is disposed in a refrigerated chamber and an upper lid that can be opened in order to provide access to the refrigerated chamber. The basket can be moved manually in horizontal direction. Therefore, U.S. Pat. No. 2,200,502 does not disclose any lifting system of the basket.

U.S. Pat. No. 2,093,856 discloses a refrigerator appliance that is suitable for being installed in a kitchen table. Such an appliance comprises a refrigerated chamber with a lower compartment and a refrigerated upper compartment that can be accessed from a front opening. A refrigeration system is disposed in the lower level. The refrigerator appliance comprises lifting means to raise the upper compartment. The lifting means are of pantograph type and comprise an electric motor that moves a worm screw that is engaged in a gear. One end of the pantograph mechanism is disposed in eccentric position in the gear. Therefore, a rotation of the gear determines a movement of the pantograph mechanism. One of the levers of the pantograph mechanism is slidingly mounted in a V-shaped horizontal slide. U.S. Pat. No. 2,093,856 is impaired by the fact that its lifting system is complicated, cumbersome and subject to jamming.

The purpose of the present invention is to eliminate the drawbacks of the prior art by devising a refrigerator appliance with pull-out trolley that is efficient, capable of guaranteeing uniform refrigeration and provided with a lifting system of the trolley that is not cumbersome, is reliable and is not subject to jamming.

Another purpose of the present invention is to provide a refrigerator appliance that is reliable, practical, versatile, and simple to make and install.

These purposes are achieved according to the invention with the characteristics of the independent claim 1.

Advantageous embodiments of the invention appear from the dependent claims.

The refrigerator appliance of the invention is defined in claim 1.

Additional features of the invention will appear more evident from the detailed description below, which refers to a merely illustrative, not limiting embodiment, as illustrated in the attached figures, wherein:

FIG. 1 is a perspective view of the refrigerator appliance according to the invention in closed position, wherein a front wall of the refrigerator chamber is omitted.

FIG. 2 is a front view of the refrigerator appliance of FIG. 1;

FIG. 3 is a side view of the refrigerator appliance of FIG. 1;

FIG. 4 is an axial sectional view taken along the plane IV-IV of FIG. 2;

FIG. 5 is a vertical sectional view taken along the plane V-V of FIG. 3;

FIG. 6 is a vertical sectional view taken along the plane VI-VI of FIG. 2;

FIG. 7 is an exploded perspective view of the trolley of the refrigerator appliance of FIG. 1;

FIG. 8 is a perspective view as FIG. 1, which shows the refrigerator appliance of the invention, in open position;

FIG. 9 is a front view of the refrigerator appliance of FIG. 8;

FIG. 10 is an axial sectional view taken along the plane X-X of FIG. 9; and

FIG. 11 is a sectional view taken along the plane XI-XI of FIG. 2.

With reference to the Figures, the refrigerator appliance of the invention is disclosed, which is generally indicated with reference numeral (100).

The refrigerator appliance (100) comprises a base (1) suitable for being positioned onto the ground. Adjustable feet (10) are connected to the base (1). A supporting frame (11) is disposed on the base (1). The supporting frame (11) may comprise four uprights (12) with L-shaped section that are disposed at the corners of the base (1).

The supporting frame (11) supports a refrigerated chamber (2). The refrigerated chamber (2) has a bottom wall (20) disposed onto the base (1). A technical compartment (13) is provided between the bottom wall (20) of the refrigerated chamber and the base (1).

The refrigerated chamber (2) has a parallelepiped shape that is obtained by means of walls fixed to the supporting frame (11) in such a way to define a refrigerated compartment (21). Two lateral walls (25), a back wall (26) and a front wall (not shown) raise from the bottom wall (20). The walls of the refrigerated chamber can be insulated panels.

The refrigerated chamber (2) is opened on top and has an upper edge (23) that defines an upper opening (22) (FIG. 7).

A refrigeration system (3) comprises a refrigeration circuit that is partially disposed in the technical compartment (13). A coolant circulates in the refrigeration circuit.

With reference to FIG. 6, a compressor (30), a condenser (31), a throttle valve (not shown) and an evaporator (32). When in operation, the condenser (31) is a warm heat exchanger, whereas the evaporator (32) is a cold heat exchanger.

The compressor (30) and the condenser (31) are disposed in the technical compartment. The refrigeration circuit passes through the bottom wall (20) of the refrigerated chamber and therefore the evaporator (32) is disposed onto the bottom wall (20) of the refrigerated chamber, inside the refrigerated compartment (21). The evaporator (32) is disposed in peripheral position on the bottom wall (20) of the refrigerated chamber. The evaporator (32) is a static evaporator comprising a heat exchanger with finned pack, a plate heat exchanger or a boxed heat exchanger.

One or more fans (33) are disposed on the bottom wall (20) of the refrigerated chamber, near the evaporator (32), in order to move a ventilated air flow inside the refrigerated compartment. The fans (32) are of axial type.

The technical compartment (13) contains a dripping tray (34) to collect the condensation that drips from the refrigeration system, and an electronic control unit (35) to control the refrigeration system.

With reference to FIG. 7, a trolley (4) is slidingly mounted inside the refrigerated compartment (21). The trolley (4) comprises a tray (40) shaped like a rectangular plate. The dimensions of the tray (40) are slightly lower than a horizontal section of the refrigerated compartment (21).

The tray (40) may comprise a light source, such as a LED, and a sheet of transparent material, such as glass, that covers the LED.

Two upper lateral supports (41) raise from the lateral edges of the tray (40). The upper lateral supports (41) can be plates provided with large openings (42).

The upper lateral supports (41) support a lid (43) that consists in a rectangular plate disposed in parallel direction to the tray and suitably dimensioned in order to close the upper opening (22) of the refrigerated chamber. Sealing means, such as gaskets, are provided in the edge of the lid (43) and/or in the upper edge (23) of the refrigerated chamber in order to hermetically close the refrigerated compartment (21) of the refrigerated chamber.

Although the figures show a tray (40) and a lid (43) of rectangular shape, the tray and the lid can have different shapes.

The height of the upper lateral supports (41) is selected in such a way that the distance between the tray (40) and the lid (43) allows to position bottles, such as wine bottles, on the tray.

A post (44) raises in central position, going from the tray (40) to the lid (43). The post (44) passes through the tray (40) and a lower portion (45) of the post extends under the tray. The post (44) can have a cylindrical shape, is internally empty (FIG. 10) and is open on the bottom.

The post (44) can be replaced by an internally empty vertical wall that acts as partition and defines two microclimates in the refrigerated chamber above the tray (40).

Two lower lateral supports (46) protrude vertically downwards from the lateral edges of the tray (40).

Sliding means (47) are disposed on the lower lateral supports (46) in such a way to protrude outwards. The sliding means (47) are rectangular blocks that are vertically aligned on each lower lateral support (46), near the front edge and the back edge of the lower lateral support.

With reference to FIG. 5, two slides (5) are disposed in vertical position in each lateral wall (25) of the refrigerator chamber, near the front edge and the back edge of the lateral wall. Each guide (5) comprises a profile provided with a groove where the sliding means (47) disposed in the lower lateral supports (46) of the trolley can slide to permit a guided sliding movement of the trolley.

The coupling between the sliding means (47) of the trolley and the slides (5) of the refrigerated chamber is based on a sliding principle, and not on a rolling principle. Therefore, the slides (5) do not need lubrication, can operate in a dry condition, do not require any maintenance and are not affected by dirt, water, chemical agents, heat or shocks.

The slides (5) and the sliding means (47) are made of a corrosion-resistant material that resists to low temperatures and humidity. The slides (5) and the sliding means (47) can be made of tribologically optimized high-performance polymers.

With reference to FIGS. 1-6, the refrigerator appliance (100) is shown in closed position, wherein the tray (40) is in the refrigerated chamber (2) and the lid (43) hermetically closes the upper opening (22) of the refrigerated chamber.

With reference to FIG. 5, when the refrigerator appliance is in closed position, the refrigerated compartment (21) of the refrigerated chamber is divided into a lower chamber (V1) under the tray and an upper chamber (V2) above the tray.

The evaporator (32) and the fans (33) are disposed in the lower chamber (V1). The objects to be cooled are disposed on the tray (40), in the upper chamber (V2).

The lower chamber (V1) is in communication with the upper chamber (V2) by means of air gaps (I1, I2) between the tray (40) and the lateral walls (25) of the refrigerated chamber. In view of the above, the cold air that is pushed by the fans (33) makes an annular travel in clockwise direction with reference to FIG. 5. The following air flows are generated: a first horizontal flow (F1) in the lower chamber (V1), a second ascending vertical flow (F2) that passes through the first air gap (I1), a third horizontal flow (F3) in the upper chamber (V2) and a fourth descending vertical flow (F4) that passes through the second air gap (I2). The upper lateral walls (41) of the trolley are provided with openings (42) that let the air pass in order to form the third horizontal flow (F3).

This refrigeration system has the following advantages:

-   -   the cold is well distributed and the humidity level inside the         refrigerated chamber (2) is uniform because the ventilation         obtained by means of the two fans (33) creates a turbulence         inside the refrigerated compartment (21), which reduces the         difference in temperature between the lower compartment (V1) and         the upper compartment (V2);     -   the temperature of the products stored in the refrigerator         appliance is reduced rapidly;     -   the ideal microclimate inside the refrigerated chamber (2) is         recovered rapidly after opening the refrigerator appliance;     -   the formation of frost on the walls of the evaporator (32) is         prevented.

FIGS. 8-10 show the refrigerator appliance (100) in open position, wherein the tray (40) is basically at the same level as the upper opening (22) of the refrigerated chamber and therefore the user can collect the refrigerated objects from the tray (40).

A lifting system (6) is connected to the trolley (4) in order to raise and lower the trolley.

The lifting system (6) comprises an electric motor (60) disposed in the technical compartment (13) and supported by the bottom wall (20) of the refrigerated chamber. The motor (60) has a reducer (61) connected to a worm screw (62) that extends vertically through the bottom wall (20) of the refrigerated chamber. The worm screw (62) is engaged in a female screw (7) disposed in the lower portion (45) of the post of the trolley.

A bracket (70) with a U-boxed frame (FIGS. 1 and 2) is fixed under the tray (40). The bracket (70) has a bottom wall (71) wherein a support (72) is fixed to support and guide the female screw (7) during the engagement of the worm screw (62). The worm screw (62) moves freely inside the post (44).

In view of the above, by actuating the electric motor (60), the worm screw (62) rotates and engages the female screw (7), vertically moving the trolley (4), which sides inside the refrigerated chamber (2), while the sliding means (47) slide inside the slides (5) in a guided way.

The worm screw-female screw lifting system (6) is not cumbersome and is not subject to jamming. Together with the slides (5), the lifting system (6) permits:

-   -   a better distribution of the load of the trolley (4);     -   a better self-alignment of the trolley (4);     -   an absorption of angular and parallelism errors between the         trolley (4) and the refrigerated chamber (2).

With reference to FIG. 11, a first microswitch (W1) and a second microswitch (W2) are disposed in a lower lateral support (46) of the trolley.

The first microswitch (W1) is suitable for detecting a lower stop (B1) disposed in a lower portion of a lateral wall (25) of the refrigerated chamber, when the trolley reaches an end-of-travel position during the closing movement.

The second microswitch (W2) is suitable for detecting an upper stop (B2) disposed in an upper portion of the lateral wall (25) of the refrigerated chamber, when the trolley reaches an end-of-travel position during the opening movement.

Considering that the trolley (4) can be provided with electric components, such as the LEDs of the tray and the microswitches (W1, W2) that need to be powered, power supply cables are connected to said electric components of the trolley and collected in a bracket (8) (FIG. 2 and) fixed to the bottom wall (20) of the refrigerated chamber.

A control panel (9) is disposed on the upper edge (23) of the refrigerated chamber, which comprises a display (90) connected to a thermometer disposed inside the refrigerated chamber (2) in order to display the temperature inside the refrigerated compartment (21). The control panel (9) comprises a keyboard or a pushbutton panel (91), for example a touchscreen, which can be used by the user. The keyboard (91) is connected to the electric motor (6) in order to raise and lower the trolley (4). Moreover, the keyboard (91) is connected to a control unit of the refrigeration system (3) in order to adjust the temperature inside the refrigerated compartment (21).

A remote control can be provided in addition to or in replacement of the control panel (9) in order to actuate the lifting system (6) and/or control the refrigeration system (3)

The refrigerator appliance (100) of the invention can be used as a free-standing appliance or can be recessed in a cabinet of a modular kitchen or in another structure, wherein the lid (43) of the appliance is at the same level as the worktop of the cabinet when the appliance is in closed position.

Numerous equivalent variations and modifications can be made to the present embodiment of the invention, which are within the reach of an expert of the field, falling in any case within the scope of the invention as disclosed by the attached claims. 

1. Refrigerator appliance comprising: a refrigerated chamber that defines a refrigerated compartment that is open on top by means of an upper opening; a trolley comprising a tray to support objects to be refrigerated and a lid connected to said tray, said trolley being slidingly mounted in said refrigerated chamber in such a way that said appliance can be in a closed position, wherein the lid of the trolley covers said upper opening of the refrigerated chamber, and an open position, wherein the tray is basically at the same level as said upper opening of the refrigerated chamber in order to collect objects from the tray; a lifting system connected to said trolley in order to raise and lower the trolley; and a refrigeration system in order to refrigerate said refrigerated compartment of the refrigerated chamber, said refrigeration system comprising a refrigeration circuit with an evaporator; said evaporator of the refrigeration system comprises a heat exchanger with finned pack, a plate heat exchanger or a boxed heat exchanger; and said refrigeration system comprises at least one fan disposed in said refrigerated compartment in the proximity of the evaporator in order to circulate a refrigerated air flow in the refrigerated compartment, wherein: said trolley comprises sliding means that are slidingly mounted in slides that extend vertically in lateral walls of said refrigerated chamber in order to permit a guided sliding of the trolley; said lifting system comprises: an electrical motor fixed to a bottom wall of the refrigerated chamber; a female screw connected to said trolley; a worm screw that extends vertically through the bottom wall of the refrigerated chamber and that is engaged in the female screw; said worm screw being actuated by said electrical motor; and wherein: said trolley comprises lower lateral supports that extend in lower position from lateral edges of the tray and said sliding means are mounted in said lower lateral supports; each slide comprises a section provided with a groove where the sliding means disposed in said lower lateral supports of the trolley can slide in order to permit a guided sliding of the trolley, wherein the coupling between the sliding means of the trolley and the slides of the refrigerator chamber is based on a sliding principle, and not on a rolling principle; and said sliding means are rectangular blocks that are vertically aligned on each lower lateral support.
 2. The appliance of claim 1, wherein two slides are disposed in vertical position in each lateral wall of the refrigerator chamber, near the front edge and the back edge of the lateral wall.
 3. (canceled)
 4. (canceled)
 5. (canceled)
 6. The appliance of claim 1, wherein the slides and the sliding means are made of a corrosion-resistant material that resists to low temperatures and humidity.
 7. The appliance of claim 6, wherein the guides and the sliding means can be made of tribologically optimized high-performance polymers.
 8. The appliance of claim 1, wherein said female screw is supported by a support mounted in a bracket that protrudes in lower position from said tray of the trolley.
 9. The appliance of claim 1, wherein said trolley comprises a post or wall that is internally empty and raises in central position from said tray and is provided with a lower portion that protrudes in lower position from said tray and receives said female screw in such a way that said worm screw can move inside said post or wall.
 10. The appliance of claim 1, wherein said evaporator is a static evaporator.
 11. The appliance of claim 1, wherein said heat exchanger of the evaporator is disposed inside the refrigeration compartment on a bottom wall of the refrigeration chamber.
 12. The appliance of claim 1, wherein the refrigerated compartment of the refrigerated chamber is divided into a lower chamber under the tray where the evaporator and the fan are disposed, and an upper chamber above the tray, wherein the objects to be refrigerated are stored, the lower chamber being in communication with the upper chamber by means of air gaps provided between the tray and the lateral walls of the refrigerated store.
 13. The appliance of claim 12, wherein said trolley comprises upper lateral supports that raise from lateral edges of the tray to support said lid, air gaps being provided between said lateral walls of the refrigerated chamber and said upper lateral supports of the trolley in order to let the air pass through.
 14. The appliance of claim 1, wherein said tray comprises a LED lighting fixture and a sheet of a transparent material disposed on the LED lighting fixture. 